Rotary engine



(No Model.)

O. H. BACON.

ROTARY ENGINE.

N0.28o-,438. f Patenteduly s, 1883.

N. PETERS, Pnaxo-mhagmphnr, washington. D.c.

UNTRD "STATES PATENT lli-FICE CHARLRS H. BACON, or ROSTON, ASSIGNOR or CNR-HALF To ARTHUR FULLER AND EUSTIS NEVHALL OF BROOKLINE, MASSACHUSETTS.

OF LYNN, AND JOHN H. STUK-GIS,

ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 280,438, dated July 3, 1883.

Application filed November 171 18H2.

To al whoml t may concern:

Be it known that I, CHARLES H. BACON, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Rotary Engines, of which the following description, Ain connection with the accompanying drawings, is aspeciiication, like letters on the drawings representing like parts.

My invention relating to rotary engines is embodied in an engine of that class in which a rotating drum or piston carrierv provided with a series of radially-movable wings or pistons rotates on a shaft eccentrically placed in a cylinder, the crescent-shaped space between the piston-carrier and cylinder receiving the fluid that is to aotuate the pistons, or, in the case of a pump or blower, is to be forced by them. In engines of this class the induction and eduction ports have usually been made in the sides or curved walls of the external cylinder, that are engaged by the ends of the pistons, and the said pistons have been forced out against the said surface either by being connected in opposite pairs guided simultaneously by the opposite walls of the said cylinder, or in some instances independent pistons have beenemployed and retained in contact with the cylinder at their outward ends by a stationary integnal piston-guide, the snrface of which is cohcentric with the said cylinder, acting on the inner ends of the said pis-A tons. As the pistons have to be radial or always at the same angle relative to the periphery of their carrying-drum, and the latter is eccentric to the external cylinder and internal piston-guide, it will be seen that the said pistons during the greater part of their revolution are not .at right angle to their guidingsurfaces, and that the distance between the said surfaces measured on the line of the piston is not uniform. In order to obviate this the pistons have to be made in two portions, separated by springs, one acting on the inner and one on the outer surface; but even when constructed in this manner the pistons bind between the two surfaces and the friction and wear are very great. The bearing-surfaces of the pistons do not usually accurately fit the external cylinder, they usually being of smaller (No model.)

curvature and touching the cylinder only along a'narro w strip-a condition which also involves rapid wear. the ports in the side or curved surface of the cylinder permit the actuating-fluid to press against the ends of the pistons as well as their sides, thus forcing them against the internal guide, and greatly increasing their friction thereon.

The present invention has for its obj ect to obviate these Objections; and it consists, mainly, in the following details of construction: The inlet and Outlet ports are in the ends or heads of the cylinder, leaving the sides or curved portions unbroken, so that the pistons may maintain a uniform contact therewith throughout their entire revolution, and the said pistons have bearing portions of a curvature the same as that of the cylinder, so that their entire end surfaces are in Contact with the said cylinder, the said bearing portions being connected with the main portion of the piston by a cylindrical joint, which admits ofthe variation in angular position of vthe piston relative to the surface of the cylinder. This prevents the pressure of the fluid on the end of the piston, reduces the wear to the minimum, and affords an accurately ground joint between the piston and the cylinder. y

The pistons have an internal bearing portion connected with the main portion by a longitudinal sli ding or telescopicj oint, the said parts being acted upon by springs tending to separate them or elongate the piston; and the inner ends, instead of being acted upon by a Xed guide concentric with the outer cylinder, have between them a loose ring,which may be called a separating-ring, as it tends to force the said pistons apart, and, reacting against them, keeps them each and all pressed outward into contact with the cylinder. The said ring, being loose, will find its proper position within the pistons, it remaining substantially concentric with the outer cylinder, but rotating with the pistons, so that only a very slight friction is developed between it and the said pistons, owing to the different centers about which they turn, the said friction absorbing practically none ofthe power of the machine, as it This construction .and making' acts in opposite direction on opposite sides of the ring.

Figure l is a side elevation of a rotary engine with one of the cylinder-heads and a por tion of the piston-carrier removed to better show the construction of the parts; Fig. 2, a mainly horizontal section thereof on the dotted line ai as,- Fig. 3, an elevation of one of the cylinder-heads, showing its inside face and the inlet and outlet ports; and Figs. 4, 5, and 6, details showing the construction ofthe pistons.

rlhe general principle of operation of the piston-carrier A, its series of pistons B movable in radial slots 2 in the said carrier, and revolving therewith in a cylinder, C, eccentric to the shaft D of the said carrier, and provided with inlet and outlet passages E F on either side of thc plane passing through the axis of both cylinder and piston-carrier, is well known, and the combination of the said parts, broadly, forms no part of the present invention.

The inner curved surface, 3, of the cylinder C is unbroken, and the passages E F, instead of opening through the said surface into the cylinder, open into chambers a b, formed in the cylinder behind its inner surface, 3, upon which the ends of the pistons B slide, and the said chambers communicate with recesses c in the heads or ends G H of the cylinders, the said recesses forming ports opening into the interior of the cylinder for the admission and discharge of the fiuid, as best shown by the arrows, Fig. 2. The inner surface, 3, of the cylinder C thus affords a uniform bea-ring for the ends of the pistons throughout their entire movement, and the said pistons are provided with bearing-pieces d, having a surface, 4, of the same curvature as and accurately fitting upon the inner surface, 3, of the cylinder, and a cylindrical surface, 5, having its axis or center of curvature at the middle point of the bearing-surface 4, and :fitting a correspending seat in the end of the main portion of the piston that works in the slots 2 of the carrier A, thus permitting the said main portion to rock slightly upon the said surface 5 as it changes its angular position relative to the surface of the cylinder in revolving therein, as shown in Fig. l. By this construction the entire surface of the end of the piston is always in perfect contact with the cylinder, and the fluid never has an opportunity to act upon the said end of the pistons, tending to force them radially inward through the slots 2 toward the center of the piston-carrier, and a sufficiently large contactingsurface is afforded to resist the wear, and a perfect t is always maintained, as the said surfaces slowly wear away.

The pistons are kept pressed radially outward through the slots 2 into contact with the surface of the cylinder C by a separating-ring, e, placed loosely within a chamber, f, in the piston-carrier, and forming an abutment for the inner ends of the pistons, by which they are prevented from moving inward, as shown in Figli., the said ring remaining substantially concentric with the cylinder C and rotating with the pistonearrier and pistons, it being carried along by the said pistons, instead of having them rub over its surface, as is the case when a fixed piston guiding surface is employed. rlhe pistons have inner bearing por tions, h, having one or more stems, fi, iitted to slide longitudinally in sockets k in the main portion ofthe pistons, springs m being inserted in the said sockets, and tending to force the said inner bearing portion and main portion apart, or to elongate the piston, and thus acting, when the piston is inserted between the separating-ring e and the surface of the cylinder C, to press the end of the piston against the said cylinder. The stems fi have a longi tudinal groove, as shown at 6, to prevent the fluid from being trapped in the socket 7n beneath the said stems. The inner bearing-surface of the portion h of the .piston is cylindrical, its radius being equal to the difference be tween the radius ofthe internal surface of the cylinder C and that of the external surface of the ring e, or, in other words, when the pistons are in place, as in Fig. l, the axis oil' the said inner bearing-surface coincides with the middle line of the outer bearing-surface, 4, of the piston, so that the actual distance bctween the points of contact of the ends of the piston with the cylinder and ring remains constant, although the said pistons areinclined to the surfaces of the said ring and cyli nder. By making the ring c loose it equalizes the pressure of the different pistons upon the cylinder due to the force of the springs m, the said ring yielding slightly if the springs m of one piston are stronger than the average. rlhere will be a slight rubbing back and forth of the inner surfaces ofthe pistons upon the ring e,- but this will not be sufficient to cause any considerable wear, and will not absorb any appreciable amount of power, as the average velocity of the Contacting-suriaecs is the same.

The piston-carrier A is made in two pieces, to enable the pistons and their separatingring to be put in place. One of the said pieces (shown in Fig. 1j consists of a drum having a hub portion, a, to receive the shaft 1'), and portion o, provided with the radial slots 2for the pistons, the said piece being wider than the piston in the direction of the axis of the shaft, as shown in Fig. 2, so that one side of it forms a circular plate, j), connecting the hub and slotted portions, the said plate portion working in a recess, 1', in the cylinder-head G, so that the side edges of the pistons have a tight iit upon the said cylinder-head. The other portion of the piston-carrier consists of a corresponding plate, t, attached to the slotted portion o, as by screws, and working in a recess, u, in the other cylinder-head, I-I.

It is obvious that by positively rotating the shaft D and connected piston-carrier the apparatus may be employed to force a iiuid, if desired.

I am aware that pistons of rotary pumps IOO IlO

l have been made having an independent bearing portion with a pivotal connection with the main portion of thepiston, andl do not broadly claim such construction.

l am also aware that it is not new to use a loose separating-ring in connection with a series of radially-movable pistons in a rotary engine.

I claim- In a rotary engine, the combination of the cylinder, having anunbroken concave surface of uniform curvature throughout and inlet and outlet ports in its heads or ends, with the piston-carrier and its shaft eccentric to the said cylinder, and the pistons radially movable in the said carrier, and provided with bearing` portions having a cylindrical -surface fitted to the said cylinder, and an opposite cylindrical surface entering a corresponding` seat in the main portion of the piston,whereby uniform contact is always maintained between the cylinder and pistons, and the latter are never subjected to endLpressure, substantially as and for-the purpose described.

In testimony whereof Ihave signed my naine to this specification in the presence of two subscribing witnesses.

CHARLES H. BACON. 

